1. Field of the Invention
The present invention relates to a vehicle lamp, in which a light source and a lens arranged on a front side of the lamp form a predetermined light distribution pattern.
2. Description of the Related Art
In a vehicle lamp such as a cornering lamp or a lamp unit of a headlamp, light from a light source arranged on an optical axis extended in a front and rear direction of the vehicle lamp is deflected and irradiated in a forward direction of the vehicle lamp by a lens arranged on a front side of the vehicle lamp, thereby forming a predetermined light distribution pattern.
For example, JP-A-2005-141918 describes an example of a cornering lamp, and JP-A-2005-44683 and JP-UM-A-4-21005 describe examples of lamp units of headlamps.
Further, JP-A-2005-183090 describes a projector-type lamp unit in a headlamp, in which a surface shape of a projecting lens thereof is set to a shape different from that of a normal projecting lens.
A vehicle lamp such as a cornering lamp or a lamp unit of a headlamp is frequently arranged along a shape of a vehicle body of a vehicle. Therefore, it is preferable to promote a degree of freedom of layout of the lamp and promote design performance of the vehicle by forming a lens thereof by a surface shape along the shape of the vehicle body.
However, the vehicle lamps described in JP-A-2005-44683 and JP-UM-A-4-21005 use plane-convex lenses, and the vehicle lamp described in JP-A-2005-141918 uses a lens having a front surface of an ellipsoid shape. Therefore, none of these described lenses are formed along a shape-of the vehicle body. Thus, there is a problem that the lenses are insufficient in promoting degree of freedom of a layout of a lamp and of vehicular design.
Further, although the projecting lens of the lamp unit described in JP-A-2005-183090 is provided with a surface shape different from that of a normal projecting lens, the surface shape is provided with some degree of regularity and is not constituted by a surface shape in conformity with the shape of the vehicle body.
Further, even when the surface on the front side of the lens is formed by a freely formed curve surface in line with the shape of the vehicle body, a desired light distribution pattern cannot accurately be formed only by such a formed surface.